The present invention relates to an apparatus for the purification of the liquid metal for cooling the core of a fast neutron reactor comprising a heat insulating envelope immersed in the reactor core and suspended from the protective slab surmounting the latter, a removable plug disposed in said slab and giving access to the upper part of the inside of the envelope and, within the latter, means for cooling a liquid metal flow taken from the reactor core to a temperature which ensures the solidification of impurities, means for filtering the cooled liquid metal, means for the at least partial heating of the purified metal prior to its return to the reactor core and a valve for regulating the purified metal flow returned to the core.
Known apparatuses of this type have the disadvantage that the purified liquid metal flow regulating valve is located in the lower part and as the liquid metal to be purified, generally an alkaline metal such as sodium, can only be removed from the lower part of the apparatus the purified liquid metal is reheated by indirect heat exchange in countercurrent with the liquid metal to be purified, so that it is necessary to remove the complete purification apparatus from the reactor vessel when said valve has an operating fault. Such a removal constitutes a long and delicate operation, due to the radioactivity of the liquid metal in which the reactor core is submerged.